Loss of heterozygosity 1p/19q and survival in glioma: a meta-analysis.

BACKGROUND

Glioma is rarely curable, and factors that influence the prognosis of glioma patients are not fully understood. Loss of heterozygosity (LOH) of 1p/19q has long been known to be a typical molecular signature of oligodendroglial neoplasms. However, whether LOH of 1p/19q is associated with survival in gliomas remains controversial. Here our goal was to evaluate the association between LOH of 1p/19q and progression-free survival (PFS) and overall survival (OS) by conducting a meta-analysis among glioma cases.

METHODS

The PubMed and Embase databases were searched from the earliest records to May 2013 to identify studies that met prestated inclusion criteria. Reference lists of retrieved articles were also reviewed. Three authors independently extracted information needed for further analysis. Either a fixed- or a random-effects model was used to calculate the overall combined hazard ratio (HR) estimates.

RESULTS

Twenty-eight eligible studies involving 3 408 cases were included in the meta-analysis. Compared with the chromosomal intact group, codeletion of 1p and 19q was associated with a better PFS (HR = 0.63; 95% CI, 0.52-0.76) and OS (HR = 0.43; 95% CI, 0.35-0.53). Subgroup analyses showed this association to be independent of detection methods and the grades and subtypes of gliomas. Furthermore, isodeletion of chromosome 1p predicted a similar favorable disease outcome (PFS: HR = 0.68; 95% CI, 0.47-0.97) (OS: HR = 0.51; 95% CI, 0.35-0.75), especially in low-grade gliomas, whereas isodeletion of 19q only indicated longer PFS (HR = 0.70; 95% CI, 0.56-0.87).

CONCLUSION

Codeletion of 1p and 19q is associated with better survival rates in glioma. Isodeletion of 1p predicts similar outcomes but to a lesser extent, whereas the effects of isodeletion of 19q remained only marginal.